I've ordered a BH860 with my 4225h. On paper, apart from the longer reach the 860 has a slightly lower breakout force, not surprising given it is (apparently, so said my dealer) the same hydraulics but longer geometry. And it hangs slightly longer and higher during transport, so it's a slight reach versus manoeuvrebility tradeoff. My dealer said no major difference in build quality or functionality otherwise.
In my instance, dealer had an 860 in stock, at a price derived from 2018 list price. While he would have had to order in a 760, subject to a new price list with a currency adjustment (I'm in Canada) not in our favour. So my choice was clear; you may face a bigger price difference.
(Not sure I'm telling you anything you don't know already....and thanks for pointing me in the direction of Branson a few months ago in the first place....)